1. Field of Invention
The present invention relates to a light emitting device and a manufacturing method thereof. In particular, the present invention relates to an organic electro-luminescence device and a manufacturing method thereof.
2. Description of Related Art
With rapid advancement of semi-conductor devices and displays, the multimedia of modern societies proceeds more quickly. In respect of displays, owning to extraordinary features such as higher quality, better space utilization, lower power consumption and free of radiation, the flat panel display has gradually replacing traditional displays as the mainstream of the marketplace nowadays.
The flat panel display includes liquid crystal display (LCD), organic electro-luminescence display (OEL display), plasma display panel (PDP), etc. Here, the electro-luminescence device is a dots matrix type display having emissive devices. Also, the OEL device owns characteristics: no viewing angle restriction, low manufacturing cost, high response speed (up to a hundred times that of the liquid crystals), low power consumption, wide operating temperature range, light weight and easily miniaturized and streamlined as demanded. Hence, OEL device has the greatest potential to become the dominant type in the next generation of flat panel displays.
FIG. 1 is a cross-section schematic view of one organic electro-luminescence device (OEL device) in the prior art. Referring to FIG. 1 please, the OEL device is disposed on a substrate 100. As shown, the patterned insulating layer 120 has a plurality of openings 122 in which an anode layer 110 is disposed. Also, a light-emitting layer 130 is disposed on the anode layer 110 in the openings 122, and a cathode layer 140 is disposed on the light-emitting layer 130. During the manufacturing process of an OEL device, the ink-jet technique is usually used to fill light-emitting materials into the openings 122 to form the light-emitting layer 130. However, due to different materials of the anode layer 110 and insulating layer 120, the surfaces of the anode layer 110 and the sidewall of the insulating layer 120 have different absorption properties with respect to light-emitting materials. And thus the thickness of the formed light-emitting layer 130 is not uniform and it may lead to a phenomenon so-called lip height, as shown in FIG. 2A. Furthermore, if there is still residual light-emitting material remained on the insulating layer 120, light-emitting materials originally in both sides of the insulating layer 120 will cross over the insulating layer 120 and get blended.
The problems mentioned above would cause reduction of yield of the fabricating process and deterioration of displaying quality for the OEL device. Thus, ways to overcome the mentioned problems due to the interface of various materials between the anode layer and insulating layer and to form a uniform light-emitting layer are crucial keys to the raising of yield for the fabricating process of OEL device and the improved displaying quality thereof.